Glaciology Candidate: Amundson on " The glacier-ocean-bedrock-atmosphere quadruple junction"

Start Date/Time: Friday, March 14, 2014, 2:30 PM
Ending Date/Time: Friday, March 14, 2014, 3:30 PM
Location: JHN 102

Speaker: Jason Amundson
Title: The glacier-ocean-bedrock-atmosphere quadruple junction
Abstract: There are two locations on the terminus of a tidewater glacier where ice, water, bedrock, and air form a quadruple junction. Those two locations serve to remind us that tidewater glaciers are affected by a myriad of processes that span several disciplines. Ice flow is steered by basal topography that it helps to create; fjord circulation, which brings warm seawater into contact with glacier ice, is affected by off-shore oceanographic and atmospheric processes and by the discharge of fresh subglacial water; sea ice and dense packs of icebergs appear to affect calving and also act as a buffer between fjord waters and the atmosphere. Advances in our understanding of the dynamics of tidewater glaciers, which are currently major contributors to eustatic sea level rise, are hampered by the highly-coupled nature of these and other processes. In this talk I will illustrate some of the important couplings within tidewater glacier systems by discussing recent and on-going research at two Alaskan glaciers: LeConte Glacier, a fast-flowing and retreating tidewater glacier, and Taku Glacier, a slowly advancing tidewater glacier that is not currently calving icebergs.